Investigation Summary
Flight 964 was a scheduled service from Kutaisi to Moscow. During the approach to Domodedovo at an altitude of 900 meters, the crew reported issues with their compass. An electrical failure had rendered the primary navigation instruments, including the artificial horizons, inoperative. In the darkness and snowfall, the pilots were unable to maintain a stable heading or attitude. While performing a turn to align with the runway, the crew overcorrected a slight right bank, leading the aircraft into a terminal left-hand spiral. The Tu-104 struck power lines and crashed into a field 16 km from the airport at a high bank angle. The investigation highlighted that the failure of the 36V DC power supply led to the loss of the navigation systems, which, combined with the lack of visual references, made the crash inevitable once spatial disorientation set in.
Final Conclusions
The investigation concluded that the primary cause of the accident was a failure of the 36V DC power supply, which led to the total loss of the aircraft's compass system and main artificial horizons. In conditions of night and poor visibility (IMC), the crew suffered spatial disorientation. While attempting to navigate the approach with failed instruments, the pilots inadvertently entered a steep left bank of approximately 70 to 75 degrees, resulting in a terminal spiral dive into the ground.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Systems & Failure Modes
Electrical System
A failure in the 36V DC power supply caused the loss of critical navigation instruments.
Compass and Gyros
The failure of these instruments led to the crew losing spatial orientation in night/IMC conditions.
Interesting Facts
- 01The aircraft was a Tupolev Tu-104B manufactured in 1960.
- 02An electrical failure disabled the main gyros and compass system during the approach.
- 03The aircraft entered a steep left bank of 75 degrees before impact.
- 04The crash site was located 16 km northwest of Domodedovo Airport.
- 05All 122 occupants, including 8 crew members, were killed.
Safety Actions & Advisories
Approach Stabilization
The accident reinforced the necessity of initiating a go-around maneuver when an aircraft is not properly aligned or stable on the glide path, especially in marginal weather.
Location
ACCIDENT SITE · Coordinates taken from the entered by an editor.